Lubricant



Patented Sept. 4, 1945 2,384,023 LUBRICANT Lionel S. Galstaun,

Concord, Calif., assignor to Tide Water Associated Oil Company, SanFrancisco, Calif., a corporation of Delaware No Drawing. ApplicationFebruary 1, 1943, Serial No. 474,391

7 Claim. This invention relates to a grease suitable for use inlubricating the packings and bearings of.

' drocarbon. The usual type of greases containing soaps are likewiseunsuitable because of reactivity with hydrogen chloride. Many oils ofmineral and vegetable origin are also unsuitable for either or both ofthe above reasons.

It is an object of this invention to provide a lubricant which isnonreactive with, and resistant to solution in, petroleum hydrocarbonscontaining halogen acids.

It is a further object of this invention to provide a superior lubricantfor mechanical systems operating in the presence of petroleumhydrocarbons and hydrogen halides.

Other objects and purposes will be made apparent in th followingdisclosure.

In the isomerization of normal paraflins t isomeric forms, anhydroushydrogen chloride is used as a catalytic promoter. Subsequently to thecatalytic reaction the hydrogen chloride is generally condensed at a lowtemperature, usually at about 40 F., with the hydrocarbon reactionproducts obtained from the process. The mixture of hydrocarbon and HClis then pumped to a stripping column where HCl is stripped from thehydrocarbon portion and recycled to th reactors.

The lubrication of the ing the stripping column and elsewhere in theprocess, is a considerable source of trouble, not only from the point ofview of selecting a proper packing, but from the lubricant side as well.Commercially available greases containing soaps of various kinds areunsuitable because the soaps and hydrogen chloride combine to formmetallic chloride and free organic acid. The oil contained in theoriginal grease may then be either blown out of the packing causingimmediate failure of the packing or else it may partially dissolve inthe hydrocarbon, and eventually cause failure of the packing from. Ineither case, experience has shown a life of from a few hours to a day ortwo for the packing when lubricating with ordinary grease. Such frequentoverhauls would be ruinous to an otherwise continuous process.

Many vegetable oils, and their combinations pumps used in chargby lossof lubricant therewith vegetable waxes were also found unsatisfactory.It appears that the basic trouble in many of these combinations is therelatively unsaturated nature of many of these oils as exemplified byrelatively high iodine numbers.

X Various lubricating compositions with low iodine absorption numbers,either with Or without fillers, hav given some satisfaction, but theirperiod of useful operation is still short. Examples of such lubricantsare petroleum, saturated fats, and saturated fatty acids, to which maybe added mica, graphite, asbestos, or other filler. The life of suchcompositions is generally only two or three times that of the ordinarycup rease.

According to the present invention lanolin is used as a lubricating baseto which is added about 10% of flake or powdered graphite. Pump packingsregularly lubricated with this composition have given consistently sixweeks or more of satisfactory service on pumps continuously operated onmixtures of light hydrocarbons and hydrochloric acid. Like packings inthe same service lubricated frequently with cup grease gave only one ortwo days service before it was necessary to replace the packings. Forthis type of service the lanolin itself has excellent lubricatingproperties. It is entirely non-reactive with hydrogen halides underconditions of normal temperature and at all pressures we haveinvestigated (up to 350 lbs. per square inch). It is but sparinglysoluble in aliphatic hydrocarbons. However, lanolin, when used byitself, readily works out of the packing gland during operation of thepump shaft and, consequently, requires frequent servicing. The additionof the graphite gives a structure to the mixture which substantiallyretards this tendency to work out of the gland.

A combination of lanolin containing about 10% by weight of graphite hasa light greasy consistency particularly adapted for application by meansof the usual grease guns and pressure fittings. According to the mode ofapplication used and the service requirements of the lubricant asomewhat harder compound may be prepared, if desired, by adding smallamounts of beeswax. In preparing a lubricant for the packing glands ofpumps, compressors, and similar equipment in continuous operation notmore than about 15% of beeswax should be added. Higher proportions mayimpair the flow of the grease in the packingduring operation. Suchlarger proportions may be added, if desired, in other applications whereflow of the lubricant under operating conditions is not essential. Anexample of an application where larger proportions of beeswax may beadvantageous is in the lubrication of. valves and valve stems which areonly occasionally sublubricant.

Any suitable method'for compounding the lanolin and graphite will besatisfactory. An advantageous procedure comprises melting the lanolinand adding the graphite while stirring the mixture. I v about 240 F. forfrom one-half to three hours -while agitating will aid .in finaldehydration. However, it is generally preferable to start with anhydrous-lanolin. If graphite of sufiiciently fine particles is used, noappreciable settling of graphite will occur on cooling. Consequently,powdered graphite is preferred in the manufacture 'of the lubricant.

Maintaining the temperature at The amount of graphite used may vary fromabout 1% to about 20%, depending on service requirements, but about 10%is preferred. Its function is largely to act-as carrier for the lanolinon the packing. The graphite particles are generally firmly held in theinterstices of th packing and serve to maintain a, supply of lubricant.Accordingly, the following formula is suggested:

.Per cent Anhydrous 1anolin 99-65 Graphite" l-20 Beeswax a 0-15 Analternative method of application compfises making a graphite-lanolinconcentrate and applying this to the packing prior to installation. Suchconcentrate may contain as much as 50% by weight of graphite. In thiscase, straight lanolin, (anhydrous) may be injected into the packingfrom time to time during operation.

Some care should be used in the selection of packings. Generally anasbestos fibre packing is best. Suitable asbestos packings are marketedby most manufacturers. Cotton duck packings are definitely inferior andtheir use is not recommended for ftCl-hydrocarbon systems. In thepresence of butane and HCl, for example, cotton duck packings arealtered to hard inelastic slatelike masses. Asbestos packings are not soaffected. Certain rubber bonded and metallic packings have been found tobe satisfactory.

Commercial packing materials listed above as suitable or theirequivalents may be either hotdipped or otherwise impregnated with thiscomposition prior to use. Such procedure would simplify for the consumerthe installation of the packings for HCl-hydrocarbon service.

I claim:

1. A.lub'ricating composition adapted for use in the lubricationofsurfaces exposed to mixtures of hydrogen halides and hydrocarbons whichcomprises a major portion of substantially anhydrous lanolin and a minorportion of graphite.

2. A composition according to claim 1 in which amount of graphitepresent is from 1% to 3. A composition according to claim 1 in which theamount of graphite present is about 10%.

4. A composition according toclaim 1 in which the amount of graphitepresent is from 20% to 5. A lubricating composition adapted for use inthe lubrication of equipment exposed to mixtures of hydrogen halides andhydrocarbons which has the following approximate formula: substantiallyanhydrous lanolin 99% to graphite 1% to 20%; and beeswax 0% to 15%.

6. An asbestos packing material for packing glands impregnated with amixture of substantially anhydrous lanolin and graphite, the percentageof graphite in said mixture being between 1% and about 50% and the majorcomponent of said mixture being lanolin.

7. The method of lengthening the life of an asbestos fibre packing in agland exposed to hydrocarbons mixed with hydrogen halides, whichconsists in first impregnating the packing with a concentrate ofanhydrous lanolin 50% to by weight and finely divided graphite 50% to20%, and thereafter, from time to time, injecting further anhydrouslanolin into the packing under pressure while in place in the gland, thegraphite serving as a carrier for the lanolin and retarding its flow outof the gland.

LIONEL S. GALSTAUN.

